Thank you. Of course it would be very interesting to run some actual numbers. But intuitively, it seems a little odd that the Milankovitch forcing gives the climate a little nudge on the way up but grabs it around the neck on the way down.
I lost you. Why do you say it does this?
Think about it for a minute. You seem to be saying that the Milankovitch cycle alone does not cause temperature to rise. Instead, it also triggers a feedback loop that involves CO2. By analogy, it’s like pushing a ball that then rolls from a higher position to a lower position.
That’s all well and good, but it seems odd that when the Milankovitch force turns in the opposite direction, the ball promptly rolls back uphill, so to speak.
You would need to do the math to see if it works, but as I say, it’s intuitively troubling to me.
I don’t understand why you think one direction is “downhill” and the other is “uphill”. And, just to be clear, the feedback loop operates in both directions.
Actually, I don’t even think the ball analogy is very good. There is not really an instability that I can tell. (There does seem to be some difference between the warming and cooling directions because ice sheets can probably break up faster than they can build up…but I don’t think either way should be thought of as unstable. Again, the effect of the CO2 feedback loop is to magnify the change in temperature…and apparently also to link the two hemispheres…not to cause a true instability.)
I’m guessing because he’s reading the ice cores backwards. I think he’s looking at a graph where the x-axis is depth rather than time; as a result, the present is at the left instead of the right and he’s confused.
He would not be the first climate change skeptic I’ve debated who has done it.
As something interesting I read today I thought I’d toss in this article:
Whether these guys are the last, desperate remnants of the anti-AGW skeptics or a new wave of scientists fighting against the main stream view of GW I don’t have any idea. Just thought I’d toss in the article here as this is the only GW type thread currently on the front page in GD.
-XT
Alrady referred to in post 57 and replied to in post 58
Sorry, must have missed that. Carry on.
-XT
You didn’t read carefully. I am not admitting anything. Re-read your question, and then my answer, and then laugh at yourself for screwing up your “simple yes or no” question.
Except that I prove it plausible.
No, and if you had quoted beyond the initial “Yes”, you’d know exactly why - the reasoning for the temperature drops are obvious to most people who have taken more than five seconds to think about this problem.
Take a look at negative forcing factors in the IPCC links I provided (it’s Figure 6-6 in the 3AR and I forget the reference in the 4AR). Now consider how those forcings have changed over time; specifically, how legislation in the 1970’s might have affected them.
Five seconds of critical thinking - that’s what it takes to figure out this perceived contradiction.
Five seconds of critical thinking - that’s what it takes to destroy your argument.
Yes. Because he’s addressing a different point than I am. I never said my calculation was precise, only accurate.
Despite your love for yes or no questions, you seem to have extraordinary difficulty answering them.
Yes or no: Do you accept my first order calculation as proof that CO[sub]2[/sub] is competent to affect the temperature changes we see?
This is a question that has been asked of you now 3 times.
Then you have no point to make. If you’re using the standard definition of sensitivity as climatologists use it:
Then this line is intuitively obvious:
I answered this question prior to you asking it. You’re grandstanding on a non-existent platform.
You have two independent variables and one dependent; there exists no such graph in the IPCC report (all the SRES data is temperature vs. time and CO[sub]2[/sub] vs. time), so if you are not fabricating this data, you should have a 3-D graph of temperature vs. CO[sub]2[/sub] output and climate response to CO[sub]2[/sub].
Link me to such a graph since you’re convinced it exists. You don’t need to quote it or paste it; just provide the link and I will click on it myself.
Great, then that’s exactly what the data shows.
But you specifically denied that scenarios have the same sensitivity, since in post #7 you claimed to group according to “sensitive” and “non-sensitive”:
It seems like you’ve just taken 100 posts to agree with what I posted in post #23.
If you haven’t noticed, I’ve taken to not only quoting your old posts, but giving an exact post number so that you cannot weasel out of anything you’ve said in the past.
No, I contend that human well being has clearly been improved by increases in temperature, and that wealth and technology are only correlating, not causative.
You are free to cite the IPCC to prove me wrong.
Global warming has caused a 99% drop in our GDP over the past century and we’d all be living to 150 and 100x richer if it hadn’t been for global warming.
You are free to cite the IPCC to prove me wrong.
So in other words, you’re conceding that it is not impossible for global warming to outweigh economic growth.
Welcome, now to post #1 - let’s see what science actually says about global warming; after that, you can make an educated judgement about how serious the problem is.
You claim to have an open mind to the evidence - so why do you classify looking through data to support my position? If the data doesn’t support my position, then read the relevant sections and point out why I’m wrong. If the data does support my position and you have an open mind, then read the relevant sections and learn why you’re wrong.
Except I have not pointed to a long document. I have pointed you to an exact subchapter, and pointed you to a single figure which sums up the data.
I neither participate regularly in the temperature thread nor the economic hockey stick thread, and I specifically created this thread to avoid all the problems with proxy temperature data.
But you have a good point - I’ll find your response on the other thread and respond (I have to sift through the entire thread so don’t expect it right away), and as far as this thread is concerned, I’ll post quotes from the IPCC 4AR (you’ll still need to do your own research if you want the equivalent quotes from the 3AR or CCR).
I don’t need a research assistant.
I’ve done my research.
Have you done your own research?
I’d vote for “last, desperate remnants”. In fact, three of the four authors are well-known skeptics who have been around for quite some time now. (The fourth is apparently a grad student.)
It is also worth noting that in a press release (and news stories such as the one you picked up), the authors have gone considerably further in what they say than what apparently they have actually published (at least judging from the paper’s abstract and from what I can glean from the RealClimate discussion…I don’t have access to the actual article).
Let’s be careful to differentiate between two groups of people.
(1) Scientists skilled enough in climatology to be qualified peer reviewers. Among these people (people with expertise, who I’ll call “experts” for lack of a better term), the popularity of an argument doesn’t matter. One expert standing against 999 experts cannot be dismissed or ignored. The strength of the data is paramount, with the caveat that you must be an expert to assess the strength of the data.
(2) For the 99% of us who aren’t experts - and this includes politicians, political groups, mainstream media, and even well-respected scientists in non-climatology fields - the situation is a little different. We are not qualified to review the primary data - did they use the Raman cross-section of CO[sub]2[/sub] to estimate radiative forcing? Should they have? Hell if we know. We aren’t qualified to assess who’s right and who’s wrong, but we still need to make policy and economic choices that affect our lives. At this point, we must rely on some sort of consensus from the experts.
Do we have enough experts lining up on one side to get a pretty good picture of what’s going on? Sure we do. Global warming skeptics will trot out maybe a dozen experts who disagree. Let’s give them the benefit of the doubt and multiply that number by 10x - so on one side we have 100 “experts” who disagree with the IPCC report. We’d like to compare that to the number of people who agree with the IPCC report, but that’s really hard to count; instead, let’s just compare it to the number of authors on the IPCC report, and ignore all the non-author experts who agree. There are 700 authors of the IPCC 4AR.
No matter how you measure it, there’s a huge majority of experts who accept rather than reject the IPCC reports. For every “expert” who speaks against the IPCC, realize there’s between 7 and 200 “experts” who have spoken out in favor of it.
(The 200 figure is based on the number of pro-AGW peer-reviewed articles vs. the number of anti-AGW articles)
Sure…and don’t get me wrong here, I actually DO think GW is happening…but there have been times in the past where the vast majority of scientists in the main stream ignored a few folks on the fringe. Who later turned out to be right. I was watching a show on TLC or Discovery about asteroid strikes, for instance…and they were saying that at one time the majority of geologists didn’t believe that the earth HAD been hit by large bodies, at least not in recent (geologically) times. Another one I recall was about how the continents move on plates…at one time the majority of scientists in the field didn’t believe that either. Then there is evolution…at one time most scientists didn’t go for that either.
I’m not saying that these AGW skeptics are in that category. However, just because there are only a few of them going against the main stream doesn’t necessarily make the main stream right. Jshore says these guys aren’t ‘experts’ so I’ll buy that…being at work I don’t have time to dig into their backgrounds and I trust him on that kind of thing. I just wanted to include the article as something I read as it related to the thread.
-XT
We will never know who is “right” or “wrong”. We can only assess whose opinion is “founded” versus “unfounded”.
Well, just as a caveat - I don’t know whether these guys are experts either, but there do exist out there legitimate experts who oppose global warming theory. Many self-proclaimed experts have neither expertise nor publications to back up their claims, but a few do. Richard Lindzen is one of the most prominent and most outspoken. There’s another guy in Chicago and a handful of others who shouldn’t be dismissed.
Instead, I’d listen carefully to what they’re saying. Lindzen, for instance, agrees that the data shows global warming is real and at least partially anthropogenic. He thinks the IPCC overestimated by about 3x the actual anthropogenic warming (which just means that humans are responsible for 20-30% of the warming in the past 50 years instead of 60-90%). He also thinks that future projections have been overestimated (but agrees temperatures will continue to rise). Whether he’s correct or not, his position is still closer to the IPCC report than it is to the skeptics’ position that the Earth is not heating, that humans are not a cause, and that we don’t know whether the Earth will continue to warm.
I’d love a cite for that. If they meant geologists 100 years ago, then it’s understandable given their dating methods. But more recent than that? Not that I can recall (and I was at uni studying geology when the KT impact thing was all the rage.)
That’s because no-one had come up with a mechanism and evidence i.e there wasn’t anyone on the other side. Pretty soon after the magnetic striping data came in, it was obvious. That’s the key there - the data, and a mechanism.
I’ve always been given to understand that most life scientists in England came around pretty soon after Darwin published a valid method. And on the Continent, there were people like Haekel too, although I gather France was a hotbed of Lamarkianism (also evolutionary theory, if wrong)
Well, my Google-Fu isn’t strong today…I can’t figure out even how to look this one up. I know they were talking about the guy who was digging in Arizona at Meteor Crater, and that the main stream scientists of the day were insisting that it was volcanic…not a meteor. And that the predominant theory was that large bodies didn’t impact the Earth, at least not in geologically recent times. I THINK this was less than 100 years ago as well…but as I said, my Google-Fu is weak today and I have no idea how to dig this one up.
Well, the exact mechanisms for how climate works are also little understood today, though we are gaining knowledge rapidly. My understanding though is that it is a highly complex process with many ‘forcings’, and that even today the experts don’t know exactly how it works.
Additionally, I don’t think that once the evidence was in that the theory of plate tectonics was widely accepted right away…it took time to become the main stream. There are a lot of examples where what we THOUGHT we knew turned out to be wrong…which is why science is such a great thing. It’s self correcting in the long run. Perhaps AGW will be the same…or maybe it will be like Evolution, standing the test of time. I couldn’t say to be honest…I’m not even a good amature on this subject.
-XT
Actually, I don’t think I quite commented directly on their expertise. I more commented on their history. As for expertise, the lead author David Douglass is a physicist who got interested in global warming late in his career, clearly with a strong bias in the skeptical direction. Fred Singer is trained as a physicist and electrical engineer and was, in his time, apparently a good scientist…but then got into denying the effect of CFCs on the ozone layer and then denying climate change, founding the Science and Environmental Policy Project (SEPP) to pursue these. And, he hasn’t really published very much in peer-reviewed journals in these areas.
John Christy is clearly the most mainstream published climate scientist of the bunch and I think he has a decent publication record. He is most famous for co-authoring with Roy Spencer the first analysis of the post-1979 satellite record measuring temperature trends in the troposphere. Their first analysis showed the lower troposphere to be cooling, which was a puzzle in comparison to the surface temperature measurements and something that the skeptics very definitely latched onto. Over time, various errors and necessary corrections have been found in their analysis…and so the correction of these (along with a longer data series) has led to a more and more positive temperature trend. There have also been (at least) two other groups who have done the analysis of the data from scratch and have found more positive temperature trends (although now the different analyses have converged enough that the trends may be the about same within error bars). At any rate, I think Spencer and Christy are considered to be a decent scientists, but one clearly with a strong point-of-view (and Spencer’s weird endorsement of intelligent design theory probably hasn’t helped their reputation). However, it is notable that it seemed like all the major errors that have been found in their satellite analysis pushed the temperature trend in the cooling direction relative to the corrected analysis. I doubt it was intentional but I think they may have let their preconceptions influence their science too much. It is interesting to note that, unlike with the whole Michael Mann thing, Spencer and Christy have not generally been vilified nor been the subject of witchhunts by Congressional Committees despite the large role that their erroneous analysis played in the debate. (Mind you, I think this is a good thing that this hasn’t happened…I do not endorse such action. I am just noting the interesting contrast.)
Intuitively, it seems like it should be a lot easier to push a system in the direction of a positive feedback loop than against it. As an extreme example, it’s often a lot easier to light a library on fire than to put the same fire out.
But it can’t operate in both directions at a particular temperature and CO2 level. Right?
Assuming I understand your question correctly, the answer is that it can. Take, for example, the feedback loop between CO2 and water vapor. If CO2 levels start to rise, then this warms the climate, which causes water vapor in the atmosphere to increase, which causes further warming. Thus the water vapor feedback amplifies the warming effect due to the rise in CO2. Conversely, if CO2 levels start to fall, then this cools the climate, which causes water vapor in the atmosphere to decrease, which causes further cooling. Thus the water vapor feedback amplifies the cooling effect due to the fall in CO2.
In both cases, the water vapor feedback causes an amplification of the effect due to the change in CO2 alone.
Well, I’m not going to keep ionsisting on a cite, but merely going to ask you if you agree with this:
Today, we certainly don’t seriously doubt the possibility of impact events. And the reason we don’t doubt is twofold - increased and innovative data (sampling the PGE layer at the KT boundary, improved electromicroscopy to find shocked quartz, hi-res and subsurface satellite mapping etc.) and improved computer modeling (modeling impacts and seeing how that agrees with observation).
Do you see how the same is applicable to paleoclimate studies?
Actually, acceptance of plate tectonics was so rapid and the new models so intuitive and useful in so many ways that it represents a true scientific paradigm shift. Suddenly, for those in the field, everything made so much more sense, from the igneous guys to the metamorphic guys. Within a few short years, the new theory was being applied to everything from ore body genesis models to analysis of sedimentary basins. I was lectured by professors who were grad students at US universities at the time, and they certainly conveyed to us what a sudden change it was in the entire field. The whole world figuratively lay opened up before them. Suddenly, there were answers - not just to age-old questions (why is this seashell on top of Mont Blanc) but questions they only now knew how to ask (why is the Andes subduction zone igneous terrane different from the Japanese?).
It became the mainstream practically overnight (a few short years is overnight in science)
That’s nonsense. Your actual calculation contained no variable for CO2. It’s as simple as that.
As I say, it takes most of the meaning out of your “simple calculation.” Five seconds of critical thinking, and it’s obvious your argument is wrong.
Given that the calculation didn’t even contain a variable for CO2 (see post #10) I would have to say “no.” Post #1 mentions CO2 but doesn’t contain any calculation based on the same.
I must have missed your answer – could you repeat it? Or quote yourself?
So what? I never said there was such a graph.
Let me ask you this: what are the independent variables in your analysis? What are the dependent variables?
I don’t understand your point.
That’s fine, but sometimes my quote doesn’t say what you claim it does.
For example, you claim that I “inisted” on first-order calculations (whatever that means), which I did not do. I simply asked you for a cite for your claim.
And vaccines are related to increases in temperature how?
And radio is related to increases in temperature how?
And radar is related to increases in temperature how?
Lol. That’s your bible hey? If it’s not in there it don’t matter. Lol.
It’s also possible that you’re actualy Liz Taylor. But I wouldn’t bet my life savings on it.
Classify it as what?
Sorry, but I’m not your research assistant. Besides, I already did that in another thread – with predictable results.
Anyway, I’m still waiting for an answer to my question. So simple. 0.2C over what time period?
Oh, and since you actually quoted your sources, I will take a look at them and consider them.